Archaeo-optics in Orkney Day 3: On the beach at Rackwick

The boulders on Rackwick beach are remarkable, but ultimately it was was reflections that captured my imagination.

Rackwick reflections (Video: Aaron Watson)
 

Since I started working with the optical properties of Neolithic monuments I've been thinking more generally about other effects of light that can be encountered in the natural world. Reflections are among the most common, but those that appeared on Rackwick beach this afternoon were unusual because it is possible to interact and walk across them. Similar to yesterday's optical projections inside the nearby Dwarfie Stane, the world became inverted.

(Photos: Aaron Watson)
 

How might Neolithic people have related these kinds of experiences to the projected images within the Dwarfie Stane? Could reflections have been a means of accessing a different kind of reality. Today, this certainly appeared to be the case on the beach at Rackwick.